During the textile carding process in which fiber stock is fed to the card in either loose form or in the form of a picker lap, combed and cleaned in web form, and the web condensed and packaged in coiled sliver form into a can, a significant amount of cotton dust and lint is produced which tends to pollute both the environment of the carding machine and which can then be carried by the sliver to pollute subsequent operations within the textile mill. As is well known, cotton dust and lint are a matter of great concern to textile manufacturers and manufacturers of textile machinery. The Government has imposed guidelines regarding acceptable levels of cotton dust and lint in textile plants and various means are used at present in an attempt to comply with these guidelines and provide a safe environment for operators of textile machinery. However, to date even though various pneumatic and similar type apparatus may be used in combination with textile cards to reduce cotton dust, there is still a considerable amount of the cotton dust and lint which escapes from the machines. This can be evidenced by the fact that a typical operator can observe cotton dust and lint on the housing of his carding machine and that considerable dust can be found in the ambient air when measurements are taken.
Heretofore, attempts have been made to remove dust at the carding operation through the use of various types of pneumatic apparatus adapted to the carding machine. For example, U.S. Pat. No. 3,438,093 to Rutz discloses a card flat cleaning system comprising a high pressure chamber on one side of the card from which air is blown laterally across the arcuate chamber formed by the flats to a low pressure chamber positioned on the other side of the textile card. The dirty air is then drawn out of the low pressure chamber and recycles through a conduit and filter to a blower into the high pressure chamber. A hood is provided to enclose the continuous run of flats and two blow nozzles are fluidly connected to the high pressure chamber for blowing the air laterally across the arcuate chamber and parallel to the rotational axis of the card cylinder. The Rutz patent further discloses the utilization of blow pipes having air discharging jets placed in the neighborhood of the return bends of the continuous run or belt of flats. Suction inlets coextensive with the flats are placed outside of the return bend at each end of the continuous run of flats for removing the flat waste stirred up by the two blow pipes and each suction inlet fluidly communicates with the previously described low pressure portion of the flat cleaning system. A suction inlet extending into the converging space between the licker-in and feed roller also is provided for withdrawing dust-laden air from therebetween and conveying it into the system.
It is important to note that the patent to Rutz discloses a plurality of horizontally disposed blow nozzles for blowing air laterally across the arcuate chamber above the card. These blow nozzles in combination with the blow pipes disposed adjacent and within each return bend of the continuous run of flats are intended to remove cotton dust and waste from the arcuate chamber defined by the continuous run of flats and enclosed by the hood thereabove. However, this system inherently will not function to aid in pulling cotton dust and waste from within the working space between the main card cylinder and the operative lower run of flats, a primary function of the instant invention. In fact, the air blown through the blow nozzles in a lateral direction across the arcuate chamber will tend to maintain and even force the cotton dust and fibers to remain in the working area between the main cylinder and operative flat run due to the relatively higher air pressure in the arcuate chamber created by the lateral air flow. This relative high pressure effect is enhanced by the blow pipes disposed adjacent each return bend of the continuous run of flats. The Rutz system tends to clean the card flats but the lateral air pressure blown therethrough also, at least in part, defeats the entire purpose of a card flat cleaning system of removing a maximum amount of cotton dust and waste from the textile card and thereby the operating environment of the card room and subsequent processing operations in a textile plant.